Science Common Sense

78 - What causes ocean currents?

Ocean currents are like huge rivers in the ocean. They're caused by two main things:

1. Wind: When wind blows over the ocean, it makes the water move. The stronger the wind, the stronger the current.
2. Temperature: When the sun heats the ocean water near the equator, it expands and becomes less dense. This warm water rises, and colder water from deeper down moves up to replace it, creating a current.

Together, wind and temperature differences make ocean currents that help move the ocean's water around the world.